1. Field of the Invention
The present invention relates to a method of manufacturing an ink-jet recording head.
2. Description of the Related Art
Hitherto, ink-jet recording apparatuses have been widely commercialized and utilized in, e.g., output devices of computers, etc, for the reasons that the running cost is relatively low, the apparatus size can be reduced, and the ink-jet recording apparatus is easily adaptable for color image recording using inks of plural colors.
On the other hand, an energy generating element for generating energy to eject ink from an ejection orifice of a recording head is practiced, for example, as the type using an electro-mechanical transducer, e.g., a piezoelectric element, or the type irradiating electromagnetic waves emitted from, e.g., a laser for heating ink and ejecting ink droplets by the action of the heating. Another known example of the energy generating element is the type heating a liquid by an electro-thermal transducer having a heating resistor.
In particular, a recording head of the ink-jet recording of the type ejecting ink droplets by utilizing thermal energy is advantageous in that ejection orifices can be arrayed at a high density and an image can be recorded at a high resolution. Above all, a recording head using an electro-thermal transducer as energy generating element is effective in easily reducing a head size. Further, the recording head using the electro-thermal transducer is advantageous in that the recording head can be manufactured by sufficiently utilizing merits of the IC techniques and the micro-machining techniques where advancement and reliability have been recently progressed and improved to a remarkable extent in semiconductor fields, and that the recording head can be easily manufactured at a higher density packing and at a lower cost.
In recent years, a method of manufacturing a nozzle, which ejects ink, with a high degree of accuracy by employing the photolithography has also been utilized to perform recording at a higher definition. Of late, a recording head having a longer recording width is further demanded from the viewpoint of realizing recording of an image at a higher speed and a higher definition. More specifically, there is a demand for a recording head with a length of 10.16 cm (4 inches) to 30.48 cm (12 inches), for example.
When trying to realize the recording head having such a long recording width by forming a larger number of recording elements on a single recording element substrate, the length of the recording element substrate is so increased as to cause the problem that the recording element substrate is more susceptible to, e.g., cracks and warping. Another problem of the recording element substrate having a very long size is that the yield of the recording element substrate itself reduces in the manufacturing process.
One proposal for overcoming the above-mentioned problems is to arrange, on an integral carrier, a plurality of recording element substrates each having a nozzle array which includes an appropriate number of nozzles, and to realize a recording head having a large recording width as a whole. The proposed construction requires that nozzles of the recording element substrates adjacent to each other are partly overlapped and are accurately arranged to prevent gaps and overlaps from generating in a printed image. In particular, when photographic print is intended or when an even longer recording head is to be formed, requirements for the accuracy in nozzle positions are further increased. Above all, in an overlapped region between the recording element substrates adjacent to each other, a deviation of the nozzle position is more apt to appear as a streak in the printed result, and the nozzle position is especially required to satisfy an even higher degree of accuracy.
PCT Japanese Translation Patent Publication No. 2003-525786 discloses a method for coping with the problem that thermal expansion generated by a temperature rise during the use causes an alignment failure of a head module due to a difference in linear expansion between the head module and a supporting member. With the disclosed method, the head module is held in a properly aligned state at the temperature during the use, while it is not in the properly aligned state at temperatures other than that during the use.
However, the disclosed method is just intended to cope with the position deviation caused by the difference between the temperature during the manufacturing and the temperature during the use. In other words, the disclosed method does not take into consideration various deviations that may generate in the recording element substrate throughout the entire manufacturing process. If those various deviations generate, the recording element substrate and the positions of nozzles formed therein cannot be arranged at the intended positions with a high degree of accuracy.